Many mobile and stationary machines employ drive systems that transmit mechanical energy from an input end to an output end for performing various tasks. Where control of certain drive system output parameters (e.g., speed, torque, direction of rotation or travel, etc.) is desired, mechanical devices, such as gearboxes, are commonly connected between the input end and the output end of the drive system. A gearbox typically includes a number of components that work together to transmit power, such as gears, shafts, and bearings, that are protected from their surroundings in a sealed container. The components within a gearbox are usually immersed in or supplied with a lubricant to reduce friction and keep the internal components cool during operation. Over time, the components within the gearbox can wear and/or fail, and the lubricant can degrade or become contaminated with debris, thereby requiring periodic maintenance and/or replacement.
Gearbox maintenance and replacement requires that the associated machine be temporarily taken out of service, which can decrease productivity. One way to reduce loss of productivity is to reduce the likelihood of unexpected component failures by performing regularly scheduled maintenance during periods of anticipated downtime. However, certain operating practices and harsh operating conditions can expedite the wearing of gearbox components and lubricant, resulting in a need for unscheduled maintenance and/or repairs. Predicting when unscheduled maintenance or repairs will be needed can be difficult due to widely varying operating practices and jobsite conditions.
One attempt to monitor the health and performance of a gearbox is described in U.S. Patent Application Publication No. 2012/0025526 A1 (the '526 publication) of Luo et al. that published on Feb. 2, 2012. The '526 publication describes a gearbox monitoring system for a wind turbine having a rotating blades attached to a shaft for driving a generator. The shaft is connected to the generator via a gearbox. A number of sensors associated with the gearbox measure gearbox performance during operation of the wind turbine. These sensors include tachometers that measure shaft speed, strain gauges that measure torque experienced by the turbine, accelerometers attached to bearings that detect mechanical vibrations, bearing temperature sensors, and an oil particle counter that measures debris within a gearbox lubricant. A computer connected to each of the sensors compares signals from the sensors to design limitations and generates a warning when the operating conditions exceed the design limitations. The controller may also determine that a gearbox component is damaged when the signals from the sensors exceed a threshold and automatically shut down the turbine when damage is detected.
Although the system of the '526 publication may be able to determine when the performance of a gearbox exceeds its design parameters or has been damaged, it may not be optimum. In particular, the system of the '526 publication may allow an operator to know when the gearbox is in need of maintenance or repair only after damage has occurred. Further, the system of the '526 publication may only convey the health of the gearbox in terms of whether or not current performance parameters are within design limitations and may not account for other aspects and/or factors of gearbox health.
The monitoring system of the present disclosure solves one or more of the problems set forth above and/or other problems of the prior art.